FORAMINOUS SURFACE MEANS IN A THERMOPLASTIC YARN REBOUND TEXTURIZING APPARATUS
United States Patent 3859697
In a bounce crimping apparatus for texturizing multi-filament thermoplastic yarn including a yarn texturizing chamber, a means for introducing heated fluid into the yarn texturizing chamber for drawing yarn into the chamber, a foraminous surface transversely positioned across the longitudinal fluid outlet of the yarn texturizing chamber, a platen means underlying the foraminous surface for supporting the foraminous surface against the outlet of the yarn texturizing chamber and a means for collecting texturized yarn in a condition substantially free from longitudinal tension; the improvement comprising the foraminous surface including an upper screen surface operable to overlay at least a portion of the platen and a downwardly projecting locater tab connected to the upper screen surface for engagement with the underlying platen to fixedly and reliably orient the upper screen surface wherein a rough texture of the upper screen surface is reliably and accurately oriented in a direction coincident with the axis of the lateral outlet of the yarn package chamber.
US Patent References:
Process for crimping textile yarn
Weiss et al. - November 1964 - 3156028
APPARATUS FOR CRIMPING THERMOPLASTIC YARNS
Nechvatal et al. - July 1969 - 3457611
METHOD AND APPARATUS FOR PNEUMATICALLY DEPOSITING A WEB
Jackson - December 1969 - 3485428
APPARATUS FOR THE MANUFACTURE OF CRIMPED BULKY FILAMENTS
Hino et al. - November 1973 - 3773453
PROCESS AND APPARATUS FOR JET-TEXTURING YARN AT HIGH SPEED
Breen et al. - January 1974 - 3781949
Process for crimping textile yarn
Weiss et al. - November 1964 - 3156028
APPARATUS FOR CRIMPING THERMOPLASTIC YARNS
Nechvatal et al. - July 1969 - 3457611
METHOD AND APPARATUS FOR PNEUMATICALLY DEPOSITING A WEB
Jackson - December 1969 - 3485428
APPARATUS FOR THE MANUFACTURE OF CRIMPED BULKY FILAMENTS
Hino et al. - November 1973 - 3773453
PROCESS AND APPARATUS FOR JET-TEXTURING YARN AT HIGH SPEED
Breen et al. - January 1974 - 3781949
Application Number:
05/429056
Publication Date:
01/14/1975
Filing Date:
12/28/1973
View Patent Images:
Export Citation:
Assignee:
Chevron Research Company (San Francisco, CA)
Primary Class:
Other Classes:
425/224
International Classes:
D02G1/00; D02G1/16; D02G1/16
Field of Search:
28/1.3,1.4,72.11,72.12 57/34B,157F 226/7,97 302/25,63 425/223,224
Primary Examiner:
Rimrodt, Louis K.
Attorney, Agent or Firm:
Burns, Doane, Swecker & Mathis
Claims:
What is claimed is
1. In bounce crimping apparatus for texturizing multi-filament thermoplastic yarn including;
2. A bounce crimping apparatus as defined in claim 1, wherein the improvement further comprises:
1. In bounce crimping apparatus for texturizing multi-filament thermoplastic yarn including;
2. A bounce crimping apparatus as defined in claim 1, wherein the improvement further comprises:
Description:
BACKGROUND OF THE INVENTION
This invention relates to an apparatus for texturizing synthetic thermoplastic yarn. More specifically, the invention relates to an improved apparatus for bounce crimping thermoplastic yarn.
Synthetic thermoplastic yarn materials, as produced, are composed of continuous, straight, smooth filaments. Such yarns have little bulk, and their utility in textile applications is rather limited.
In order to enhance the bulk and texture of synthetic yarns as required for many end uses, a variety of crimping processes have been used in the past. For thermoplastic yarns, a basic technique is to bend the yarn filaments and heat the yarn while the filaments are in bent or crimped configurations.
Recently, a basic advance has been achieved in texturizing thermoplastic yarn. This texturizing technique, known as a rebound or bounce crimping process, yields strikingly improved results as far as crimp quality is concerned.
Bounce crimping entails hurling yarn, by a heated fluid, through a jet in a continuous stream-like flow against a foraminous surface upon which the yarn impinges and from which the yarn instantaneously rebounds or bounces. The impact of the yarn upon the foraminous surface axially buckles and crimps individual filaments of the yarn while the heated fluid passes through the foraminous surface. The texturized yarn progresses without tension and substantially by rebound inertia away from the crimping zone and is guided to a collection station where the yarn is heated and then cooled to heat set the crimp prior to winding upon a storage spool.
Thermoplastic yarn texturized by the foregoing bounce crimping process possesses, inter alia, exceptional covering power and a high degree of resiliency as disclosed in U.S. Miller et al Pat. No. 3,686,848 issued Aug. 29, 1972.
The basic process and apparatus for practicing the process is featured in U.S. Clarkson Pat. No. 3,665,567 issued May 30, 1972. In brief summary, the Clarkson structure entails feeding a yarn through an elongate slender tube by a jet stream and hurling the yarn against a foraminous generally cylindrical cap mounted within a texturizing chamber. The yarn is thereby crimped or texturized and freely rebounds through a lateral outlet in the texturizing chamber and into a tubular passage for conveying the yarn to a receiver for heat setting.
Notwithstanding singular advantages provided the synthetic textile industry by the above noted Clarkson bounce crimping process and apparatus, room for significant improvement remains. In this connection, the foraminous cylindrical cap structure typically comprises an inverted cup-shaped screen. The screen is woven from warp and weft wires extending at right angles to each other, and, due to the tension relationships during weaving, there is a surface texture difference discernible when one moves a finger over the surface first in a warpwise and then in a weftwise direction. One direction is notably rougher than the other, and in this description such direction will hereinafter be referred to as the rough screen surface direction. In order to produce the most advantageous texturizing during a bounce crimping process the rough screen surface direction should be parallel with the axis of the lateral outlet in the texturizing chamber. Accordingly, it would be highly desirable to provide a foraminous surface which would insure proper screen texture directional mounting within the bounce crimping apparatus which would maintain the proper screen orientation during a subsequent texturizing operation. Further it would be desirable to provide a foraminous surface which would permit ready removal and replacement by relatively untrained personnel while insuring proper placement and orientation of the screen texture so as to facilitate a subsequent texturizing operation.
OBJECTS AND BRIEF SUMMARY OF THE INVENTION
Objects
In light of the foregoing, it is a general object of the invention to provide an improved yarn rebound texturizing apparatus which will obviate or minimize deficiencies and provide enhanced characteristics of the type previously described.
It is a particular object of the invention to provide an improved bounce crimping apparatus wherein a preferred orientation of a foraminous surface within a texturizing chamber is insured during installation and maintained during a texturizing operation.
It is another object of the invention to provide an improved bounce crimping apparatus wherein a foraminous surface within a yarn texturizing chamber may be readily removed and replaced by relatively untrained personnel while insuring proper placement and orientation to facilitate a subsequent texturizing operation.
Brief Summary
A bounce crimping apparatus according to a preferred embodiment of the invention intended to achieve at least some of the foregoing objects includes a yarn texturizing chamber, a means for introducing heated fluid into the yarn texturizing chamber for drawing yarn into the chamber, a foraminous surface transversely positioned across the longitudinal fluid outlet of the yarn texturizing chamber, a platen means underlying the foraminous surface for supporting the foraminous surface against the outlet of the yarn texturizing chamber and a means for collecting texturized yarn in a condition substantially free from longitudinal tension.
The foraminous surface comprises an upper screen portion operable to overlay at least a portion of the platen and a downwardly projecting locater tab connected to the upper screen surface for engagement with the underlying platen to fixedly and reliably orient the upper screen surface wherein a rough texture of the upper screen surface is reliably and accurately oriented in a direction parallel with the axis of the lateral outlet of the yarn texturizing chamber.
THE DRAWINGS
Further objects and advantages of the invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is a front elevational view, partially broken away, of a bounce crimping apparatus for texturizing synthetic thermoplastic continuous filament yarns;
FIG. 2 is a cross-sectional view taken along section line 2--2 in FIG. 1 and discloses a bounce crimping chamber and a lowermost foraminous surface according to a preferred embodiment of the invention;
FIG. 3 is a bottom view taken along directional arrow A in FIG. 2 and discloses an underlying supporting platen and a foraminous bounce crimping surface according to a preferred embodiment of the invention;
FIG. 4 is a cross sectional view taken along section line 4--4 in FIG. 2 and discloses a plan view of a foraminous surface positioned upon an underlying platen according to a preferred embodiment of the invention;
FIG. 5 is a cross-sectional detailed view of a foraminous member according to a preferred embodiment of the invention; and
FIG. 6 is a bottom view of a foraminous member disclosing the direction of relative rough texture of the foraminous member.
DETAILED DESCRIPTION
Basic Structure of the Invention
The improvement of the subject invention is in specific combination with a bounce crimping apparatus according to the above referenced Clarkson U.S. Pat. No. 3,665,567. The entire disclosure of this Clarkson patent is hereby incorporated by reference as though set forth at length. Briefly, however, the basic bounce crimping structure of the subject combination invention may be appreciated by reference to FIG. 1 which discloses an elevational view, partially broken away, of a bounce crimping apparatus 10.
A multi-filament synthetic thermoplastic yarn 12 is fed from a supply package (not shown) to a first driven godet roll 16 with skewed separator roll 14 and then to a second driven godet roll 20 with skewed separator roll 18. Godet rolls 16 and 20 may be heated and rolls 18 and 20 advance the yarn at a much greater speed than do rolls 14 and 16 so that the yarn 12 is drawn between the two sets of rolls.
From roll 18 the yarn 12 advances to a yarn texturizing station indicated generally by reference character 22 and then into a heating chamber 24 where the yarn is heated in a loose mass substantially free from tension. The yarn passes downstream of the heating chamber 24 into a cooling chamber 26 where the yarn is cooled again is a loose mass substantially free from tension. The yarn 12 is then drawn from the cooling chamber 26 in the form of a strand over idler rolls 27, 28 and 29 by a pair of rolls 32 and 34. From godet roll 32 the yarn 12 advances over idler roll 36 to a standard takeup mechanism where the yarn is wound in a package 38 for storage and shipment.
Referring to FIG. 2 the yarn texturizing station 22 includes a yarn tube 42 which passes through a steam plenum chamber 44 formed by a plumbing tee 46 (note FIG. 1). The plumbing tee 46 is connected through a steam valve 48 to a steam pipe so that steam may be fed to the plenum chamber 44 as regulated by valve 48.
The tube 42 passes completely through steam plenum chamber 44 and terminates within a yarn passage chamber 50. The yarn passage chamber 50 extends beneath the lower end of the tube 42 and is continued as a bore 54 in an adapter housing 56. The diameter of the bore 54 is the same as the internal diameter of the yarn chamber 50 so that a single diameter cylindrical passage is provided for the yarn as the yarn exits from tube 40 until it reaches a yarn exit opening 60 within the side of the adapter housing 56.
The external lower end of the adapter housing 56 has a convex configuration surrounding the lower end of the bore 54. An improved foraminous member 62, discussed in detail hereinafter, closes the lower end opening of the bore 54 to the passage of yarn while simultaneously permitting steam to longitudinally pass through the openings in the member 62.
The adapter housing 56 is fitted with a coaxial collar 64 which serves as an adapter for connection of the bore 54 with a steam exhaust conduit 66. By the provision of the exhaust conduit, steam passing through foraminous member 62 may be drawn off by a blower (not shown).
The above described texturizing station 22 serves to texturize or crimp thermoplastic yarn, introduced into tube 42 by the technique of "rebound" or "bounce" crimping. In this connection, the thermoplastic yarn 22 is heated as it advances through the yarn tube 42 and is picked up by the steam at the exit end thereof. The plastic yarn is then hurled longitudinally with great force by the downward flow of steam toward the foraminous member 62. The bulk of the steam passes through member 62, while the yarn 12 rebounds or bounces from screen 62 instantaneously and in a continuously moving strand-like stream to flow upwardly and to the left into an outlet tube 68. From the outlet tube 68 the yarn is deposited into a yarn treating chamber 74 comprising part of the heating chamber 24.
As noted in FIG. 1, the heating chamber 24 consists of an outer sleeve of insulation 70 which surrounds a steam chamber 72, which in turn encompasses an inner cylindrical yarn treating chamber 74. Steam is circulated through chamber 72 to heat the wall about the yarn treating chamber 74, and consequently to heat the yarn contained within the chamber 74.
The rebounded texturized yarn 12 falls into the yarn receiving chamber 74 in a condition substantially free of longitudinal tension. As the yarn 12 is withdrawn from the cooling chamber 26 by godet rolls 34 and 36, the loose mass of yarn within the heating chamber 24 progresses downwardly through the heating chamber.
To further assist in heating the yarn within chamber 74, hot air bleed tubes 76 are disposed vertically within the chamber 74 and are provided with apertures spaced at regular intervals throughout the longitudinal extent thereof. Air heated in the steam chamber 72 is blown from the apertures within bleed tubes 76 into chamber 74 to circulate through the mass of yarn within the chamber 74 and insure uniform heating of the texturized yarn.
As previously noted, immediately beneath the heating chamber 24 there is disposed a cooling chamber 26 comprising the bottom leg of a J-tube formed by the heating chamber 24 and the cooling chamber 26. The yarn passes through the cooling chamber 26 still in a loose untensioned mass. To assist in cooling the yarn two air bleed tubes 78 are disposed within and on opposite sides of the cooling chamber 26. Air at ambient temperature is blown through the cooling tubes 78 and out through apertures within the tubes along the longitudinal length thereof to circulate through the yarn mass to cool the yarn and exit through an opening 80 within a top portion of the cooling chamber 26.
Not until this point when the yarn has been fully heat set and cooled is the texturized yarn subject to longitudinal tension. As noted in FIG. 1, the yarn 12 is now withdrawn from the cooling chamber 26 over a baffle 82 and through an eyelet 84 which tends to remove gross tangles in the yarn. To further remove any persistant tangles a series of tension vanes 86, 88, 90 and 92 are provided. These vanes are simply thin pieces of sheet metal shaped to close the chamber and pivot at hinges 94, 96, 98 and 100, respectively, so that gravity will pivot the tension vanes against a wall 102 of the chamber.
The yarn thus untangled advances in a substantially linear form over idler rolls 28, 30 and 32 by pull-out godet rolls 34 and 36 to be wound upon a package 40 in a conventional manner, as previously noted.
Improved Foraminous Surface Aspect of the Invention
Referring now specifically to FIGS. 2-6 there will be seen an improved foraminous member 62, according to a preferred embodiment of the invention. More particularly the foraminous member 62 comprises a screen having a generally rectangular or square yarn texturizing surface 104 and a downwardly projecting locater tab or lip 106.
The foraminous surface is woven from warp and weft wires extending at right angles to each other, and, due to the tension relationships during weaving, there is a surface texture difference discernible when one moves a finger over the surface first in a warpwise and then in a weftwise direction. One direction is notably rougher than the other. Maximum yarn texturizing is provided if the direction of rough texture is parallel with the outlet passage 60 or the longitudinal axis of the outlet tube 68. More particularly, and with reference to FIG. 6, if the texturizing screen surface 104 were stroked in the direction of arrow A, the surface would feel rough relative to the sensation generated by stroking the planar surface of the screen in the direction of arrow B.
The improved foraminous surface 62 is mounted at the base of the yarn texturizing chamber adapter 56 by being first placed upon a platen 108 having a rectilinear ledge or surface 110 (FIG. 4) and a rectangular aperture 112 extended therethrough. The texturizing surface 104 of the improved foraminous member 62 is dimensioned so as to completely overlie the aperture 112, thus blocking movement of yarn 12 through the aperture while permitting free passage of steam.
In order to accurately and reliably orient the direction of the rough screen over the aperture 112, the lip 106 is bent at right angles to the rough direction A. Accordingly the platen may be removed, such as illustrated in FIG. 4, and a new screen 62 readily inserted in place by merely engaging the lip or tang 106 with the ledge 110 of the platen. By the provision of tang 106 the generally rectangular texturizing surface 104 may be readily and reliably postured such that the rough texture is pointing in a direction coincident with the axis of the outlet opening 60 and the outlet tube 68 to maximize texturing during the bounce crimping operation.
SUMMARY OF MAJOR ADVANTAGES
In describing a preferred embodiment of the subject bounce crimping apparatus, several highly advantageous aspects of the invention have been delineated.
In brief summary, however, the foraminous texturizing surface 104 may be accurately and reliably positioned with respect to a platen and the outlet opening in the bounce crimping chamber to insure that the rough direction of the foraminous surface projects toward the outlet passage in the bounce crimping chamber. By the provision of the downwardly projecting tab 106 which cooperates with surface 110 of the platen the texturizing screen may be readily serviced and replaced by even untrained personnel, while insuring proper orientation of the screen with respect to the texturizing chamber outlet.
While the invention has been described with reference to preferred embodiments, it will be appreciated by those skilled in the art that additions, deletions, modifications and substitutions, or other changes not specifically described, may be made which will fall within the purview of the appended claims:
This invention relates to an apparatus for texturizing synthetic thermoplastic yarn. More specifically, the invention relates to an improved apparatus for bounce crimping thermoplastic yarn.
Synthetic thermoplastic yarn materials, as produced, are composed of continuous, straight, smooth filaments. Such yarns have little bulk, and their utility in textile applications is rather limited.
In order to enhance the bulk and texture of synthetic yarns as required for many end uses, a variety of crimping processes have been used in the past. For thermoplastic yarns, a basic technique is to bend the yarn filaments and heat the yarn while the filaments are in bent or crimped configurations.
Recently, a basic advance has been achieved in texturizing thermoplastic yarn. This texturizing technique, known as a rebound or bounce crimping process, yields strikingly improved results as far as crimp quality is concerned.
Bounce crimping entails hurling yarn, by a heated fluid, through a jet in a continuous stream-like flow against a foraminous surface upon which the yarn impinges and from which the yarn instantaneously rebounds or bounces. The impact of the yarn upon the foraminous surface axially buckles and crimps individual filaments of the yarn while the heated fluid passes through the foraminous surface. The texturized yarn progresses without tension and substantially by rebound inertia away from the crimping zone and is guided to a collection station where the yarn is heated and then cooled to heat set the crimp prior to winding upon a storage spool.
Thermoplastic yarn texturized by the foregoing bounce crimping process possesses, inter alia, exceptional covering power and a high degree of resiliency as disclosed in U.S. Miller et al Pat. No. 3,686,848 issued Aug. 29, 1972.
The basic process and apparatus for practicing the process is featured in U.S. Clarkson Pat. No. 3,665,567 issued May 30, 1972. In brief summary, the Clarkson structure entails feeding a yarn through an elongate slender tube by a jet stream and hurling the yarn against a foraminous generally cylindrical cap mounted within a texturizing chamber. The yarn is thereby crimped or texturized and freely rebounds through a lateral outlet in the texturizing chamber and into a tubular passage for conveying the yarn to a receiver for heat setting.
Notwithstanding singular advantages provided the synthetic textile industry by the above noted Clarkson bounce crimping process and apparatus, room for significant improvement remains. In this connection, the foraminous cylindrical cap structure typically comprises an inverted cup-shaped screen. The screen is woven from warp and weft wires extending at right angles to each other, and, due to the tension relationships during weaving, there is a surface texture difference discernible when one moves a finger over the surface first in a warpwise and then in a weftwise direction. One direction is notably rougher than the other, and in this description such direction will hereinafter be referred to as the rough screen surface direction. In order to produce the most advantageous texturizing during a bounce crimping process the rough screen surface direction should be parallel with the axis of the lateral outlet in the texturizing chamber. Accordingly, it would be highly desirable to provide a foraminous surface which would insure proper screen texture directional mounting within the bounce crimping apparatus which would maintain the proper screen orientation during a subsequent texturizing operation. Further it would be desirable to provide a foraminous surface which would permit ready removal and replacement by relatively untrained personnel while insuring proper placement and orientation of the screen texture so as to facilitate a subsequent texturizing operation.
OBJECTS AND BRIEF SUMMARY OF THE INVENTION
Objects
In light of the foregoing, it is a general object of the invention to provide an improved yarn rebound texturizing apparatus which will obviate or minimize deficiencies and provide enhanced characteristics of the type previously described.
It is a particular object of the invention to provide an improved bounce crimping apparatus wherein a preferred orientation of a foraminous surface within a texturizing chamber is insured during installation and maintained during a texturizing operation.
It is another object of the invention to provide an improved bounce crimping apparatus wherein a foraminous surface within a yarn texturizing chamber may be readily removed and replaced by relatively untrained personnel while insuring proper placement and orientation to facilitate a subsequent texturizing operation.
Brief Summary
A bounce crimping apparatus according to a preferred embodiment of the invention intended to achieve at least some of the foregoing objects includes a yarn texturizing chamber, a means for introducing heated fluid into the yarn texturizing chamber for drawing yarn into the chamber, a foraminous surface transversely positioned across the longitudinal fluid outlet of the yarn texturizing chamber, a platen means underlying the foraminous surface for supporting the foraminous surface against the outlet of the yarn texturizing chamber and a means for collecting texturized yarn in a condition substantially free from longitudinal tension.
The foraminous surface comprises an upper screen portion operable to overlay at least a portion of the platen and a downwardly projecting locater tab connected to the upper screen surface for engagement with the underlying platen to fixedly and reliably orient the upper screen surface wherein a rough texture of the upper screen surface is reliably and accurately oriented in a direction parallel with the axis of the lateral outlet of the yarn texturizing chamber.
THE DRAWINGS
Further objects and advantages of the invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is a front elevational view, partially broken away, of a bounce crimping apparatus for texturizing synthetic thermoplastic continuous filament yarns;
FIG. 2 is a cross-sectional view taken along section line 2--2 in FIG. 1 and discloses a bounce crimping chamber and a lowermost foraminous surface according to a preferred embodiment of the invention;
FIG. 3 is a bottom view taken along directional arrow A in FIG. 2 and discloses an underlying supporting platen and a foraminous bounce crimping surface according to a preferred embodiment of the invention;
FIG. 4 is a cross sectional view taken along section line 4--4 in FIG. 2 and discloses a plan view of a foraminous surface positioned upon an underlying platen according to a preferred embodiment of the invention;
FIG. 5 is a cross-sectional detailed view of a foraminous member according to a preferred embodiment of the invention; and
FIG. 6 is a bottom view of a foraminous member disclosing the direction of relative rough texture of the foraminous member.
DETAILED DESCRIPTION
Basic Structure of the Invention
The improvement of the subject invention is in specific combination with a bounce crimping apparatus according to the above referenced Clarkson U.S. Pat. No. 3,665,567. The entire disclosure of this Clarkson patent is hereby incorporated by reference as though set forth at length. Briefly, however, the basic bounce crimping structure of the subject combination invention may be appreciated by reference to FIG. 1 which discloses an elevational view, partially broken away, of a bounce crimping apparatus 10.
A multi-filament synthetic thermoplastic yarn 12 is fed from a supply package (not shown) to a first driven godet roll 16 with skewed separator roll 14 and then to a second driven godet roll 20 with skewed separator roll 18. Godet rolls 16 and 20 may be heated and rolls 18 and 20 advance the yarn at a much greater speed than do rolls 14 and 16 so that the yarn 12 is drawn between the two sets of rolls.
From roll 18 the yarn 12 advances to a yarn texturizing station indicated generally by reference character 22 and then into a heating chamber 24 where the yarn is heated in a loose mass substantially free from tension. The yarn passes downstream of the heating chamber 24 into a cooling chamber 26 where the yarn is cooled again is a loose mass substantially free from tension. The yarn 12 is then drawn from the cooling chamber 26 in the form of a strand over idler rolls 27, 28 and 29 by a pair of rolls 32 and 34. From godet roll 32 the yarn 12 advances over idler roll 36 to a standard takeup mechanism where the yarn is wound in a package 38 for storage and shipment.
Referring to FIG. 2 the yarn texturizing station 22 includes a yarn tube 42 which passes through a steam plenum chamber 44 formed by a plumbing tee 46 (note FIG. 1). The plumbing tee 46 is connected through a steam valve 48 to a steam pipe so that steam may be fed to the plenum chamber 44 as regulated by valve 48.
The tube 42 passes completely through steam plenum chamber 44 and terminates within a yarn passage chamber 50. The yarn passage chamber 50 extends beneath the lower end of the tube 42 and is continued as a bore 54 in an adapter housing 56. The diameter of the bore 54 is the same as the internal diameter of the yarn chamber 50 so that a single diameter cylindrical passage is provided for the yarn as the yarn exits from tube 40 until it reaches a yarn exit opening 60 within the side of the adapter housing 56.
The external lower end of the adapter housing 56 has a convex configuration surrounding the lower end of the bore 54. An improved foraminous member 62, discussed in detail hereinafter, closes the lower end opening of the bore 54 to the passage of yarn while simultaneously permitting steam to longitudinally pass through the openings in the member 62.
The adapter housing 56 is fitted with a coaxial collar 64 which serves as an adapter for connection of the bore 54 with a steam exhaust conduit 66. By the provision of the exhaust conduit, steam passing through foraminous member 62 may be drawn off by a blower (not shown).
The above described texturizing station 22 serves to texturize or crimp thermoplastic yarn, introduced into tube 42 by the technique of "rebound" or "bounce" crimping. In this connection, the thermoplastic yarn 22 is heated as it advances through the yarn tube 42 and is picked up by the steam at the exit end thereof. The plastic yarn is then hurled longitudinally with great force by the downward flow of steam toward the foraminous member 62. The bulk of the steam passes through member 62, while the yarn 12 rebounds or bounces from screen 62 instantaneously and in a continuously moving strand-like stream to flow upwardly and to the left into an outlet tube 68. From the outlet tube 68 the yarn is deposited into a yarn treating chamber 74 comprising part of the heating chamber 24.
As noted in FIG. 1, the heating chamber 24 consists of an outer sleeve of insulation 70 which surrounds a steam chamber 72, which in turn encompasses an inner cylindrical yarn treating chamber 74. Steam is circulated through chamber 72 to heat the wall about the yarn treating chamber 74, and consequently to heat the yarn contained within the chamber 74.
The rebounded texturized yarn 12 falls into the yarn receiving chamber 74 in a condition substantially free of longitudinal tension. As the yarn 12 is withdrawn from the cooling chamber 26 by godet rolls 34 and 36, the loose mass of yarn within the heating chamber 24 progresses downwardly through the heating chamber.
To further assist in heating the yarn within chamber 74, hot air bleed tubes 76 are disposed vertically within the chamber 74 and are provided with apertures spaced at regular intervals throughout the longitudinal extent thereof. Air heated in the steam chamber 72 is blown from the apertures within bleed tubes 76 into chamber 74 to circulate through the mass of yarn within the chamber 74 and insure uniform heating of the texturized yarn.
As previously noted, immediately beneath the heating chamber 24 there is disposed a cooling chamber 26 comprising the bottom leg of a J-tube formed by the heating chamber 24 and the cooling chamber 26. The yarn passes through the cooling chamber 26 still in a loose untensioned mass. To assist in cooling the yarn two air bleed tubes 78 are disposed within and on opposite sides of the cooling chamber 26. Air at ambient temperature is blown through the cooling tubes 78 and out through apertures within the tubes along the longitudinal length thereof to circulate through the yarn mass to cool the yarn and exit through an opening 80 within a top portion of the cooling chamber 26.
Not until this point when the yarn has been fully heat set and cooled is the texturized yarn subject to longitudinal tension. As noted in FIG. 1, the yarn 12 is now withdrawn from the cooling chamber 26 over a baffle 82 and through an eyelet 84 which tends to remove gross tangles in the yarn. To further remove any persistant tangles a series of tension vanes 86, 88, 90 and 92 are provided. These vanes are simply thin pieces of sheet metal shaped to close the chamber and pivot at hinges 94, 96, 98 and 100, respectively, so that gravity will pivot the tension vanes against a wall 102 of the chamber.
The yarn thus untangled advances in a substantially linear form over idler rolls 28, 30 and 32 by pull-out godet rolls 34 and 36 to be wound upon a package 40 in a conventional manner, as previously noted.
Improved Foraminous Surface Aspect of the Invention
Referring now specifically to FIGS. 2-6 there will be seen an improved foraminous member 62, according to a preferred embodiment of the invention. More particularly the foraminous member 62 comprises a screen having a generally rectangular or square yarn texturizing surface 104 and a downwardly projecting locater tab or lip 106.
The foraminous surface is woven from warp and weft wires extending at right angles to each other, and, due to the tension relationships during weaving, there is a surface texture difference discernible when one moves a finger over the surface first in a warpwise and then in a weftwise direction. One direction is notably rougher than the other. Maximum yarn texturizing is provided if the direction of rough texture is parallel with the outlet passage 60 or the longitudinal axis of the outlet tube 68. More particularly, and with reference to FIG. 6, if the texturizing screen surface 104 were stroked in the direction of arrow A, the surface would feel rough relative to the sensation generated by stroking the planar surface of the screen in the direction of arrow B.
The improved foraminous surface 62 is mounted at the base of the yarn texturizing chamber adapter 56 by being first placed upon a platen 108 having a rectilinear ledge or surface 110 (FIG. 4) and a rectangular aperture 112 extended therethrough. The texturizing surface 104 of the improved foraminous member 62 is dimensioned so as to completely overlie the aperture 112, thus blocking movement of yarn 12 through the aperture while permitting free passage of steam.
In order to accurately and reliably orient the direction of the rough screen over the aperture 112, the lip 106 is bent at right angles to the rough direction A. Accordingly the platen may be removed, such as illustrated in FIG. 4, and a new screen 62 readily inserted in place by merely engaging the lip or tang 106 with the ledge 110 of the platen. By the provision of tang 106 the generally rectangular texturizing surface 104 may be readily and reliably postured such that the rough texture is pointing in a direction coincident with the axis of the outlet opening 60 and the outlet tube 68 to maximize texturing during the bounce crimping operation.
SUMMARY OF MAJOR ADVANTAGES
In describing a preferred embodiment of the subject bounce crimping apparatus, several highly advantageous aspects of the invention have been delineated.
In brief summary, however, the foraminous texturizing surface 104 may be accurately and reliably positioned with respect to a platen and the outlet opening in the bounce crimping chamber to insure that the rough direction of the foraminous surface projects toward the outlet passage in the bounce crimping chamber. By the provision of the downwardly projecting tab 106 which cooperates with surface 110 of the platen the texturizing screen may be readily serviced and replaced by even untrained personnel, while insuring proper orientation of the screen with respect to the texturizing chamber outlet.
While the invention has been described with reference to preferred embodiments, it will be appreciated by those skilled in the art that additions, deletions, modifications and substitutions, or other changes not specifically described, may be made which will fall within the purview of the appended claims: